The present invention relates to the field of micro electromechanical devices such as ink jet printers. The present invention will be described herein with reference to Micro Electro Mechanical Inkjet technology. However, it will be appreciated that the invention does have broader applications to other micro electro-mechanical devices, e.g. micro electro-mechanical pumps or micro electro-mechanical movers.
Micro electro-mechanical devices are becoming increasingly popular and normally involve the creation of devices on the xcexcm (micron) scale utilizing semi-conductor fabrication techniques. For a recent review on micro-mechanical devices, reference is made to the article xe2x80x9cThe Broad Sweep of Integrated Micro Systemsxe2x80x9d by S. Tom Picraux and Paul J. McWhorter published December 1998 in IEEE Spectrum at pages 24 to 33.
One form of micro electro-mechanical devices in popular use are ink jet printing devices in which ink is ejected from an ink ejection nozzle chamber. Many forms of ink jet devices are known.
Many different techniques on ink jet printing and associated devices have been invented. For a survey of the field, reference is made to an article by J Moore, xe2x80x9cNon-Impact Printing: Introduction and Historical Perspectivexe2x80x9d, Output Hard Copy Devices, Editors R Dubeck and S Sherr, pages 207-220 (1988).
Recently, a new form of ink jet printing has been developed by the present applicant, which is referred to as Micro Electro Mechanical Inkjet (MEMJET) technology. In one form of the MEMJET technology, ink is ejected from an ink ejection nozzle chamber utilising an electro mechanical actuator connected to a paddle or plunger which moves towards the ejection nozzle of the chamber for ejection of drops of ink from the ejection nozzle chamber.
The present invention concerns improvements to a thermal bend actuator for use in the MEMJET technology or other micro electro-mechanical devices.
There is disclosed herein a method of manufacturing a micro electro-mechanical device, the method comprising the steps of:
depositing and etching a first layer to form a first arm;
depositing and etching a second layer to form a sacrificial layer supporting structure over the first arm;
depositing and etching a third layer to form a second arm; and
etching the second layer to form a gap between the first and second arms,
wherein the first and second arms are formed from the same material having the same thermal characteristics and said gap between said first and second arms receives a bend actuator element.
Preferably the device comprises a support substrate and wherein the first arm receives current through the supporting substrate.
Preferably the first arm comprises at least two elongated flexible strips conductively interconnected at one end.
Preferably the second arm comprises at least two elongated flexible strips.
Preferably the first arm is formed from titanium nitride.